200Hz Display review/questions

Talk about overclocking displays at a higher refresh rate. This includes homebrew, 165Hz, QNIX, Catleap, Overlord Tempest, SEIKI displays, certain HDTVs, and other overclockable displays.
Q83Ia7ta
Posts: 761
Joined: 18 Dec 2013, 09:29

Re: 200Hz Display review/questions

Post by Q83Ia7ta » 11 Oct 2015, 06:49

dhaine wrote:yes it seems like there's a multiport and a singleport model with the same ref and not exactly the same panel :
I'm sure panel is same. Main board differs. My panel at X-star DP2414LED is same as in 90% of 24" 144Hz models like from BenQ, Asus, etc.

dhaine
Posts: 49
Joined: 22 Nov 2014, 00:25

Re: 200Hz Display review/questions

Post by dhaine » 11 Oct 2015, 07:04

thanks for the correction, yes indeed different main boards, with lots of difference it seems :)
I'm very sad that I bought correct version but received the multiport version :(

AustinClark
Posts: 42
Joined: 14 Mar 2015, 00:03

Re: 200Hz Display review/questions

Post by AustinClark » 14 Oct 2015, 03:31

Finally got my QNIX 2414 in today!

I got somewhat lucky with this panel I think. I'm semi-stable at a whopping 216Hz. The screen won't go white under normal conditions, though it has happened to me during a few loading screens while gaming. It takes less than a minute to go white when it's displaying pure black.

240Hz is even less stable, going white in only a few seconds when displaying pure black. Under most circumstances, however, it seems fine. Definitely stable enough to run all blur busters tests and such.

at 264Hz, the screen goes black. It doesn't work at all.

at 192Hz the screen was fine after a solid 5 minute pure-black test. This is the refresh rate I plan on using, as it's exactly 2X 96Hz, which my QNIX 2710 is overclocked too (Wasn't lucky enough to get 120Hz with it, unfortunately)

Like others, the higher I push the monitors refresh rate, the higher the gamma rises (washed out, white, weird contrasty-ness).
However, to help it a bit, you can actually take advantage of TN's shitty viewing angles! I just tilt the screen back as much as possible, and it helps to offset the issue (though not entirely, of course)

There are definitely diminishing returns going 144Hz+
It is a little smoother, but the biggest improvement is in motion clarity (ULMB would be better here, so it's really not that important). It also improves the stroboscopic effect, by creating tighter-spaced images, which is something you can only fix with higher refresh rates (that I know of).

My QNIX 2710 uses a similar power adapter as my QNIX 2414, except it outputs 5,000 mA vs 4,000mA. So, luckily, I can test with both and see if there's an improvement. I'm also considering taking the monitor apart to try cooling it better (just to be safe) and to possibly over-volt very slightly, to see if there's more headroom to be made that way. I can also test all sorts of things, like power stability (with my oscilloscope) and alternate timings. I'll be sharing my findings as soon as possible.

*EDIT
anything above 240Hz has artifacts. 250Hz causes the screen to go black immediately, just like 264Hz. All original timing

AustinClark
Posts: 42
Joined: 14 Mar 2015, 00:03

Re: 200Hz Display review/questions

Post by AustinClark » 14 Oct 2015, 04:00

More data!

Using a Kill-a-watt meter with the QNIX 2710 power supply on the QNIX 2414

75Hz = 27W
144Hz = 30W
192Hz = 33W
240Hz = 35W
240Hz (Displaying pure black) = 46W
240Hz (Displaying pure white) = 32W

all with 50% power factor

theoretical supply output? 12V * 5000 mA = 60W
Though the supply is likely terribly regulated.

The fact that more power is drawn displaying black VS white maybe be a clue as to why the monitor is failing at these high refresh rates. The time to failure also seems to be random.
The weird gamma issue is PROBABLY due to panel/LCD physics. It may not be something we can ever fix ourselves.


Extra note: The DVI cable that came with my 2414 seems a lot thicker, and is a lot shorter, than the one that came with my 2710. Perhaps the better cable will help my 2710 overclock?


*EDIT
the new power supply doesn't seem to help too much. My guess is there may be an internal regulator of some sort that is failing. Probably causing a brown-out within one of the ICs, in turn causing the LCD to stop refreshing.

AustinClark
Posts: 42
Joined: 14 Mar 2015, 00:03

Re: 200Hz Display review/questions

Post by AustinClark » 14 Oct 2015, 04:19

Interesting news

I was going to test what refresh rate exactly the screen would go black at, and found that, for some reason, I was no longer getting artifacts over 240Hz! I got NO artifacts at all up to 256Hz, and at 258Hz the screen finally would go black.
Perhaps temperature IS an issue, because I was running at the normal 144Hz when I did the test this time, but was running over 144Hz prior. Or perhaps there was less noise on the DVI cable?

This is rapidly developing. I can't sleep.

I uploaded a sample picture of the frame skip check. a dozen images captured, and zero dropped frames. I think I broke blur busters, though.
Attachments
DSC_0599b.jpg
DSC_0599b.jpg (156.26 KiB) Viewed 8637 times

User avatar
lexlazootin
Posts: 1251
Joined: 16 Dec 2014, 02:57

Re: 200Hz Display review/questions

Post by lexlazootin » 14 Oct 2015, 05:07

Take the back off and stick a fan pointing at it? maybe even buy some of these http://amzn.com/B006Z4J8JE and stick em on where ever it gets hot.

Very exciting! Might buy one.

AustinClark
Posts: 42
Joined: 14 Mar 2015, 00:03

Re: 200Hz Display review/questions

Post by AustinClark » 14 Oct 2015, 06:27

Looks like the problem is probably panel voltage. And, the good news is, that might explain some of the weird gamma effects as well!



@ 144Hz Panel Vcc = 4.75V

@ 240Hz Panel Vcc = 2.7-2.8Vish (Fluctuates, which likely explains the randomness of the failures)

Next step is to try and power the panel with my lab variable power supply, and see if that helps!


*EDIT
the "gamma" effect could be the panel not being able to provide the LCD elements the proper voltage for switching. Meaning the pixels stay whiter than they ought to, and contrast/control is mostly lost in the dark areas. This coincides with what my eyes are telling me.

Q83Ia7ta
Posts: 761
Joined: 18 Dec 2013, 09:29

Re: 200Hz Display review/questions

Post by Q83Ia7ta » 14 Oct 2015, 13:54

AustinClark wrote:the new power supply doesn't seem to help too much.
AustinClark wrote:I was going to test what refresh rate exactly the screen would go black at, and found that, for some reason, I was no longer getting artifacts over 240Hz! I got NO artifacts at all up to 256Hz
So more powerfull 5A power supply helped to get rid of artifacts?

AustinClark
Posts: 42
Joined: 14 Mar 2015, 00:03

Re: 200Hz Display review/questions

Post by AustinClark » 14 Oct 2015, 18:00

Q83Ia7ta wrote:
AustinClark wrote:the new power supply doesn't seem to help too much.
AustinClark wrote:I was going to test what refresh rate exactly the screen would go black at, and found that, for some reason, I was no longer getting artifacts over 240Hz! I got NO artifacts at all up to 256Hz
So more powerfull 5A power supply helped to get rid of artifacts?
No, all tests were done with the 5A supply. I didn't notice an immediate difference between it and the 4A, though I haven't gotten around to testing in depth. It's probably best to get a more powerful and better regulated supply if you're going to overclock, as the original is quite terrible.

I still haven't gotten around to finding and testing a temporary solution for the LCD panel voltage problem. I'll probably have to splice the power line or something. If all ends well, I'll have a stable true 240Hz panel with decent colors, which would be dreamy. Hell, a strobed backlight hack could be the next step! Could you imagine 200Hz with a strobed backlight?!?!? I believe I could use shorter strobes as a result of the higher refresh, because I'd have more strobes in a second to help maintain the average brightness. Brighter strobing and/or less persistence blur.

AustinClark
Posts: 42
Joined: 14 Mar 2015, 00:03

Re: 200Hz Display review/questions

Post by AustinClark » 15 Oct 2015, 00:22

After splicing the power lines to the LCD panel, I re-measured the voltage at 144Hz and 240Hz. The measurements this time showed a much lesser disparity. I used my lab supply to ensure the voltage stayed at just under 5V, and I couldn't tell the difference when it was off or on, even though current was flowing from my supply. Looks like I had a poor connection when measuring last time. It wasn't exactly the ideal measurement scenario, what with my contorted body, hands, and neck. Back to the drawing board :(

Post Reply